This invention relates to a circuit board device for a magnetic circuit for use in wiring an electric circuit which handles a high current, and a method of manufacturing the same.
In recent years, a so-called printed circuit board, in which an electric circuit pattern is formed by the use of printed copper foil for wiring on the front surface of an insulator blank in the shape of a thin plate, has been extensively utilized for connecting an electric circuit.
In a printed circuit board of this type, the electric circuit pattern is prepared by a copper foil etching process, and therefore the thickness of the copper foil to be used is limited. That is, the cross-sectional area of each copper foil portion to form the electric circuit is subject to a certain limitation with regard to the limited area of the circuit board. Accordingly, a printed circuit board of this type is generally used for low-current signal processing circuits, etc.
In a case where a flat magnetic circuit which handles a high current is to be formed, use is made of a circuit board device of the so-called laminated type. That is, conductor pieces which serve as portions for conducting currents are punched and then bonded on an insulating plate. Prescribed power components are properly mounted on the circuit board device for the magnetic circuit, thereby constructing the magnetic circuit.
Each of the two circuit board devices stated above has merits and demerits. By way of example, with the printed circuit board of the former, fabrication is easy but the thickness of the copper foil is limited because of the use of the etching process. Moreover, when the former is applied to a high-current circuit, problems arise due to the current capacity of the current, conducting portion, the generation of heat due to current conduction, etc. With the latter circuit board device for the magnetic circuit wherein the punched conductor pieces are bonded, the foregoing problems can be solved but additional labor is required for the steps of punching and bonding the conductor pieces. Moreover, when an electric circuit in which a low current and a high current coexist is to be formed, the steps become still more complicated. This is a problem which is difficult to solve in terms of cost.